new droid user with LG Ally

I just got the LG Ally, which is my first Droid phone. I have downloaded quite a few apps in a short time, however most are small in size, yet my hard drive is down to to 46 MB. And, my memory keeps going down, even though I have not downloaded anything. I have been told to delete apps I no longer use, but most are not even 1 MB. Is there any advice as to why this is happening?

 

The phone saves apps to the phone memory, not SD card, not sure how much the ally has, but I doubt it's more than 256, and the android OS is also on the phone memory.